1. Technical Field
Exemplary embodiments relates to memory devices, and more particularly, to semiconductor memory devices and methods of operating the same.
2. Discussion of the Related Art
A semiconductor memory device is a memory device that is embodied in a structure that uses a semiconductor for data and information storage. Examples of such semiconductors include silicon Si, germanium Ge, gallium arsenide GaAs, indium phosphide InP, etc. Semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices.
A volatile memory device loses its stored data when its power supply is interrupted. Examples of the volatile memory device include a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), etc.
A DRAM includes a plurality of memory cells being arranged in a matrix form. As the integration and the speed of semiconductor memory devices increases, a ratio of cells of the semiconductor memory devices which are failed cells that do not operate correctly is increasing. To improve yield of a semiconductor memory device, a method of efficiently repairing a failed cell may be desirable.